Parliamentary Secretaries and Ministers won't be able to receive commissions from property developers after a bill passed in the lower house of NSW parliament on Tuesday.
The NSW upper house passed the change to the ministerial code on Thursday.
Last week the Independent Commission Against Corruption heard evidence the disgraced Liberal MP Daryl Maguire sought to accept commissions from property developers.
Taped phone calls reveal when told about one such deal Premier Gladys Berijiklian congratulated him with the words; "Congrats, that's great! and "Woo hoo."
The NSW Labor Party argues Ms Berejiklian's failure to declare her relationship with Mr Maguire constitutes a breach of the ministerial code of conduct.
Member for Kogarah Chris Minns said he and fellow Labor colleagues were dismayed when they found out Premier Gladys Berijeklian's secret lover Daryl McGuire was seeking to earn commissions from property deals.
"NSW Labor and everyone in St George was shocked to learn disgraced Liberal MP Daryl McGuire was earning commissions from property deals when he was a Parliamentary Secretary," he said.
"Property developers are banned from making political donations to prevent corruption, yet commissions have been permitted and encouraged from the exact same property developers.
"That's why we need changes to the NSW Ministerial Code of Conduct to ban this behaviour. We can never have a repeat of the conduct revealed in recent weeks at the ICAC."
Labor says it has introduced further legislation to prevent all Members of Parliament from accepting such commissions.
Labor Leader Jodi McKay said: "It shocks me that we need to do this."
"But as we've heard, the Premier thinks these payments are acceptable."
"It's illegal to receive donations from property developers. It should be illegal for the very same developers to pay politicians commissions.
"We will seek support from the government and crossbench to amend the Independent Commission Against Corruption Act to ban commissions from property developers for all MPs.
"They have a job to do. Their job is to represent their community. "They should not be moonlighting with property developers and earning extra income."
Ms Berejiklian remained the focus of opposition attacks in question time on Tuesday.
The Premier was asked why she failed to report Mr Maguire's business activities to ICAC despite discussing them in recorded phone conversations.
"We should allow the integrity body to do the work it has to do," Ms Berejiklian responded.